The Australian star delved into the sport to play Charlie Kenton, a washed-up fighter who trains giant steel robots for underground competitions in the futuristic new film, which is slated for release later this year (11).

Jackman, whose father Chris was a boxer, managed to recruit retired legend and former champion Leonard to train him and when he wasn’t in the ring, the actor watched Sylvester Stallone in Rocky for inspiration.

"My old man was a boxer, actually. He was an army champ. But once I knew about this film, I did some training with Sugar Ray Leonard and another less well-known fighter in New York...,” the Daily Express quoted him as telling Total Film.

"I went back and watched the original Rocky and you forget - there was only one 10-minute fight at the end. We always said we should be able to take out boxing and replace it with anything. The sport could be snail-racing. It’s irrelevant to how well-drawn this story and these characters are."